1. Field of the Invention
This invention relates to the field of mycotoxin assays. More particularly, this invention relates to a homogeneous assay that uses changes in fluorescence polarization to detect the presence of aflatoxins in agricultural products.
2. Description of Related Art
Aflatoxins are mycotoxins produced by Aspergillus flavus molds1. Aflatoxins have been known for a long time, but their carcinogenicity was first detected in the late 1960s4. Various forms of aflatoxin, including B1, B2, G1, and G2 and many others, have been found in many forms of human foods, such as cereals, grains and peanut products9,11. Aflatoxin B1 is the most abundant of all. An exposure to aflatoxins has been associated with an increased incidence of primary hepatocellular carcinoma7.
Due to their toxicity and carcinogenicity, various analytical methods have been devised to quantitatively determine the amount of aflatoxin in agricultural products1-4,6,8. One difficulty with such assays is that aflatoxins are very hydrophobic and therefore very insoluble in aqueous solvents. Thus, mixtures of organic solvent with water have generally been used to extract aflatoxins from samples.
Another difficulty is that most of the common assays, including TLC and HPLC10, require extended cleanup steps and derivatization after extraction in order to get rid of interfering substances. ELISA methods are relatively faster but are hard to quantify due to various washing steps, liquid transfers and incubation times and cleaning steps.
Accordingly, there is a need for an assay for the determination of aflatoxins in agricultural products that is rapid, simple to apply, and that can yield quantitative results.